1. Field of the Invention
The present invention relates to an inkjet recording head and an inkjet recording device using the same, in particular, to an ink repelling treated portion at the periphery of an ink discharge portion of a head.
2. Background Art
A printer using an inkjet recording head for discharging an ink droplet from an ink discharge opening of a nozzle hole to form an image on recording paper is put into practical use and is characterized by silence and high-density printing. The printing quality of the image obtained by such an ink-jet recording head largely replies upon the position precision of dots constituting the image, which are composed of ink droplets on the recording paper. This position precision of dots is dominated by whether or not the flying direction of the ink droplet to be discharged from the ink discharge opening of the nozzle hole of the inkjet recording head is constant.
For the sake of keeping the flying direction of the ink droplet constant, it is important that the surrounding portion of the ink droplet discharge opening of the nozzle hole be in the uniform and stable surface state at the time of ink discharging, specifically it is important to realize the surface state of the surrounding portion of the ink droplet discharge opening of the nozzle hole, which is free from the matter that a part of the surrounding portion of the ink droplet discharge opening of the nozzle hole is wetted by the ink, or free from the occurrence of attachment of foreign matters such as paper powers.
In an inkjet recording head for discharging ink droplets, which are in general liquid, as small droplets from a discharge opening and attaching them to a material to be recorded such as paper to achieve recording or form an image, in order to more enhance the recording characteristic, attempts to increase the performance for smaller droplets, higher drive frequency, and the larger number of nozzles are being continued. Accordingly, a surface modification treatment for the purpose of keeping the surface state of the surrounding portion of the ink droplet discharge opening of the nozzle hole always constant becomes important more and more.
As a measure for keeping the surface state of the surrounding portion of the ink droplet discharge opening of the nozzle hole uniform and stable, there have hitherto been proposed the following two methods. That is, the first method is a method in which the nozzle plate surface including the nozzle hole and the surrounding portion of the ink droplet discharge opening of the nozzle hole is subjected to an ink repelling treatment; and the second method is a method in which in the case where an ink or foreign matters such as paper powders are attached to the surrounding portion of the ink droplet discharge opening of the nozzle hole, which has been subjected to an ink repelling treatment, the nozzle plate surface including the nozzle hole and the surrounding portion of the ink droplet discharge opening of the nozzle hole is wiped up (wiping operation) by a cleaning member made of a rubber blade, etc.
As the ink repelling treatment, there are proposed a variety of methods using water repellent materials such as fluorine-containing resins, siloxane resins, and fluorine-containing silane coupling agents. For example, there are disclosed a method of providing a plated film containing fine particles of a fluorine based resin, a method of providing a resin film containing fine particles of a fluorine based resin, a method of providing a film formed of a silicone based material, a method of providing a cured film of a fluorine based resin, and a method of providing a film made of a silane compound having a fluoroalkyl group.
In particular, as water repellent and oil repellent based resin cured films having high water repellency and oil repellency and being advantageous in film durability, there are proposed a cured film of a fluorine based resin and a heat curable epoxy resin (JP-A-11-138821 and JP-A-11-235826); a cured film formed of a fluoroolefin resin containing an active hydrogen atom-containing reactive group and an isocyanate curing agent (Japanese Patent No. 3,382,416); a cured film obtained from a self-crosslinking group-containing fluorine-containing resin and an acrylate based resin (JP-A-9-221620); and a cured film of a block copolymer constituted of a block containing a fluorine or siloxane water repellent and oil repellent component and a crosslinking group-containing non-water repellent and oil repellent block (JP-A-2001-233972).